docs: def get_bounding_box(self):
          """
          Compute surface bounding box from surface mesh representation. That is
          extract longitudes and latitudes of mesh points and calls:
          :meth:`openquake.hazardlib.geo.utils.get_spherical_bounding_box`
  
          :return:
              A tuple of four items. These items represent western, eastern,
              northern and southern borders of the bounding box respectively.
              Values are floats in decimal degrees.
          """
          mesh = self.mesh
          return utils.get_spherical_bounding_box(mesh.lons, mesh.lats)